How to count columns with the same values ​​from a table?

Question

PHP

How to count columns with the same values ​​from a table?
The column has the same values ​​chat(for example - 2) , how to count the number of these columns and display them in php?

$order = DB::$the->query("SELECT * FROM `sel_orders` where `chat` = '2' ");
$fname1 = $order->fetch(PDO::FETCH_ASSOC);

PS That is, you need to count all the columns in which chat = 2

Answer 1

mysqli_num_rows

Answer 2

SELECT count() FROM `sel_orders` where `chat` = '2' ;